Monday, August 26, 2013 at 4:00 PM

JILA Auditorium

Michael Shull, University of Colorado

"New Results from the Cosmic Origins Spectrograph: Missing Baryons, AGN, and Reionization"

Abstract:

I present a survey of ultraviolet spectroscopic observations with the Cosmic Origins Spectrograph on the Hubble Space Telescope. I will describe the current status of the local baryon census, observations and theoretical modeling of thermal phases of the intergalactic medium (IGM) and circumgalactic medium (CGM), and the extent of heavy element transport away from galaxies. Other new results include the COS composite spectrum of quasar ultraviolet continuum and emission lines (see figure), measurements of heavy elements in galactic halos, and probes of the Helium-II epoch of reionization at redshifts z = 2.5 to 3.3. We have also used COS "parallel observations" with the new Wide-Field Camera-3 to discover high-redshift galaxies likely responsible for hydrogen reionization at z = 7-8.

Back to Speakers